The conventional way to raise and lower trailers such as semi-trailers, feather-light horse trailers, recreational vehicle trailers and other such trailers is to use a manually actuated trailer jack. Conventional trailer jacks commonly include a rotatable drive shaft that can be rotated by a manually driven crank arm to raise and lower the trailer as desired. A problem with manually operated jacks is that they are hard to actuate, particularly when raising the trailer. Such manually actuated jacks are particularly difficult to operate for those individuals who have arthritis or simply do not have the strength and endurance to manually crank the jack. Such manually operated jacks are also particularly burdensome for workers of warehouses and semi-trailer yards who frequently raise and/or lower multiple trailers for connection and disconnection from semi-tractors.
There are known attempts to reduce the manual labor required in raising and lowering trailers by providing either a dedicated electrical or hydraulic jack on the trailer. However, there are several drawbacks with electrical or hydraulic jacks. Electrical or hydraulic jacks are rather expensive in comparison with the overall cost of the trailer and have not met with much commercial success. The expense problem is amplified by the fact that automatically actuated jacks are dedicated to one trailer and therefore owners of multiple trailers must buy one electrical or hydraulic jack for each trailer they own.